Gastrinomas are the most common symptomatic, malignant pancreatic neuroendocrine tumor (pNET) in patients with or without MEN1 and sufficient numbers of these patients have been entered into our protocols to allow systematic assessment. A number of different studies were completed this year. One study reported the presence of hepatic primary gastrinomas seen in patients with Zollinger-Ellison syndrome at NIH and Stanford. Of 223 ZES patients 7 patients had evidence of a primary hepatic gastrinoma. This study is the first systematic study reporting the incidence of this group of patients and their specific management problems. It is an important group because they are the second largest extra-duodenal/pancreatic location of gastrinomas, are outside the areas used examined in detail at surgery, thus would frequently be missed with the standard surgical approach. This is particularly an oversight as a proportion of these are curable surgically. A second study dealt with the success of reoperation in 52 ZES patients after an initial non-curative surgery. After reoperation 18/52 patients were initially disease-free (35%) and after a mean follow-up of 8yrs, 13/52 remained disease-free (25%). This result suggesting all ZES patients post-resection should have systematic imaging, and if tumor recurs, advise repeat operation. During this year information from our prospective studies was used to write a number of guideline/position papers or consensus review papers dealing with unmet needs in patients with NETs/pNETs which covered areas of the diagnosis of these tumors and other NETs, treatment of advanced disease and approaches to their management.